1. Field of the Invention
The present invention relates to an apparatus, a system, and a method that are suitable for use when a user searches for desired content that seems to be desirable at that time, though there is no specific target content, from a large-capacity storage device in which, for example, a large amount of musical piece content, a large amount of movie content, a large amount of electronic-book content, etc., are stored.
2. Description of the Related Art
In this specification, the term “content” is information represented by signals of, for example, music, video, electronic books (text information, such as research papers, novels, and magazines, and still-image information), guide information, Web pages, and programs (including game programs).
When a recording medium, such as an optical disc, in which content of a plurality of musical pieces are contained, is loaded into a playback device and is played back, usually, a user of the playback device selects a musical piece desired to be played back. Hitherto, when the selection and the playback of the musical piece are performed, related attribute information, such as musical piece titles and artist names, is displayed, and a musical piece is selected while viewing the display so as to instruct the playback thereof.
As the storage capacity of recording media has increased, it has become possible to store several thousands or several tens of thousands of pieces of musical content in one recording medium. Accordingly, there has been a demand for searching a recording medium in which a large amount of musical piece content is stored in this manner for desired musical piece content.
As an example of this searching method, when the related attribute information of musical piece content is displayed as described above and the displayed information is used for searching, a hierarchical structure has come to be used to store desired musical piece content.
FIG. 32 shows an example of such a hierarchical structure. In this example, search items are set as a first layer. As the search items, in the example of FIG. 32, five items are given: “artist”, “album”, “musical piece”, “genre”, and “composer”. Examples of “artist” are performers, singers, and conductors. “Album” is a group of a plurality of musical pieces contained in one CD (Compact Disc), and the groups of musical pieces are divided by album titles. “Genre” is divided according to the type, such as classical, jazz, pop, Latin, and new music.
The hierarchical structure is divided into a plurality of layers for each search item. For example, in the case of “genre”, the highest layer is a layer that is divided into groups for each type of a plurality of genres described above. Then, below that layer, layers of the items of “artist”, “album”, and “musical piece” are arranged in sequence. The “artist” layer is a layer that is divided into groups for each artist, and the “album” layer is a layer that is divided into groups for each album. The musical pieces of the lowest layer are formed of individual musical pieces, and groups of a plurality of musical pieces are arranged under the layer above the lowest layer.
As shown in FIG. 32, below the “artist” layer, “albums” and “musical pieces” are arranged in sequence. Below “album” layer, the “musical piece” layer is arranged. Below the “composer” layer, “albums” and “musical pieces” are arranged in sequence.
As another classification (grouping) method, grouping may be performed according to “'60s music”, “top 25”, “top rated”, and “recently played-back music”, and directly below that group, a group of musical pieces belonging to each group may be arranged.
When classification (grouping) is performed in the above hierarchical structure, when a layer is selected, a list of a plurality of groups contained in the associated layer is displayed as attribute information. The user is able to select a desired group from the list. When the user selects a predetermined group, the display is changed to display a list of groups of the layer below that predetermined group. When the layer of the group of musical pieces of the lowest layer is reached, the related attribute information of each piece of the musical content is displayed, and the user selects a desired musical piece by referring to the information.
For this reason, in order to reach a desired musical piece, it is necessary to frequently go back and forth through the hierarchical structure or scrolling of the list has to be frequently and repeatedly performed. As a result, as the capacity of recording media becomes even larger, the searching operation burden on the user just keeps on increasing.
Attempts have been made to reduce the searching operation burden on the user by introducing a function for searching for a musical piece using a searching function disclosed in, for example, International Publication No. WO 02/48917 A1. However, it cannot be said that this is easy to use in terms of the method of inputting search information.